Does a suitable soil provide solely biological treatment for septic tank effluent?

A suitable soil does not provide solely biological treatment for septic tank effluent. Instead, it performs a combination of physical, chemical, and biological treatment processes. When effluent from a septic tank is introduced to the soil, the soil structure allows for the filtration of solids while microorganisms break down the organic matter.

The physical aspects include the soil's ability to filter and absorb water, while chemical reactions may occur as the effluent interacts with soil minerals. This multifaceted approach ensures more effective treatment of the effluent than biological processes alone would provide. Therefore, stating that suitable soil offers solely biological treatment overlooks its other critical roles in treating septic tank effluent.